Hybrid Turbocharger

Last year Mitsubishi Heavy Industries announced their development of a new type of hybrid marine turbocharger for generating electricity with exhaust gas from the main engine. The development of the hybrid turbocharger designated MET83MAG commenced in 2008 and following successful trials concluded in May 2010, a production model was prepared for installation in Oct 2010 on board the MV Shin Koho. The technology was jointly developed by four companies: NYK, the Monohakobi Technology Institute (MTI), the Universal Shipbuilding Corporation, and Mitsubishi Heavy Industries, Ltd.

Caption: Cutaway drawing of theMET83MAG turbocharger. The generator is housed within the air intake silencer and connected to the turbocharger rotor shaft.
Image credit: Mitsubishi Heavy Industries Ltd.

The output power of the three-phase AC generator is up to 750 kW at 9,500 rpm, due to the fluctuation in output the electrical power is first rectified to DC, then converted to the
appropriate voltage and frequency for shipboard consumption. Using a hybrid turbocharger instead of a diesel generator(s), the hybrid turbocharger contributes to a further reduction of CO2 emissions.

A further benefit of the hybrid turbocharger is that the generator can act as a motor and using the turbo’s compressor stage, provide a blower function in place of an auxiliary blower for slow speed operation of the two stroke propulsion engine.

Launched in Feb of this year, the MV Shin Koho is a 180,000 dwt bulk carrier of LOA 958 ft (292 m), beam 148 ft (45 m) and draft 80.3 ft (24.5 m). She is the world’s first carrier to be equipped with a hybrid turbocharger. Powered by a single MAN B&W 7S65ME-C diesel engine of 22,225 hp (16,580 kW) at 90 rpm the top speed is 17 kn. Her present duties will be transporting iron ore from Australia.